Explosive-engine.



H. fr. CREW. EXPLOSIVE ENGINE. APPLIOATION FILED JUNE 17, 1913.

Patented Feb.'2, 1915.

3 SHEETSf-SHEBT'I.

ATTORNEY H. T. CREW. BXPLOSWE ENGINE.

` APPLIGATIVQN ILD JUNE 17, 1913 ,126,?1 3. Patented Feb. 2, 1915.

3 SHEETS-SHEET 2.

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JNVENTOR VVITNESSES H. T. CREW. BXPLOSIVB ENGINE.' APPLICATION FILED JUNE 17, 191s.

1,126,71 3. Patented Feb. 2, 1915.

3 SHEETSSHEET 3.

w ff @w Zi i WITNEssr-:s www BY a f ATTORNEY maren ernaar erstes,

HENRY THOMAS CREW, 0F SHREVEPORT, LOUISIANA, ASSIG-NQR, OF ONE-HALF T0 WILLIAM B. SIMPSON, OF SHREVEPORT, LOUISIANA.

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Specification of Letters Patent.

Fatented Een. 2, fll.

Application led .Tune 17, wld. 'Serial Ito. 774,224.

Tf1/Z 'zc/iowa, 'it may concern,

Be 1t known that l, HENRY THoMas CREW,

a citizen of the United States, residingat Shreveport, in Caddo parish, State of Louisiana, hare invented a new and useful EX- plosion-Engine, of' which the following is a specificatio This invention has reference to improve ments in explosion engines of either the two or the four cycle type, and its object is to provide means whereby greater eiliciency is obtained from the explosions than is the case with the ordinary type of explosion engines.A

Ordinarily in an explosion engine of the two or four cycle type the explosion occurs so that the impulse is delivered to the piston at approximately the point of dead center andfrorn this point to the ninety degree position of the crank shaft with respect to the dead center at which the impulse is delivered to the piston, the explosion chamber is expanding and the eiiciency of the burning gases is rapidly diminishing, wherefore at the point where .the impulse should be most eflicient it has lostv a large part of its force and the eiliciency of the engine is materially lower than it should be with the energy yrepresented by the explosion of the charge. With rthe present invention this relatively inellicient arrangement is to, a great extent eliminated for the impulse is delivered when thc crank shaft is at substantially right angles to the .line of reciprocation of the piston and consequently such impulses is de livered at the point of greatest leverage with respect to the crank` shaft.

ln accordance, with the present invention two pistons are provided in the power cylindcr, or in the event of more than one power cylinder. in each of said power cylinders, and these pistons a rc connected to the crank shaft in quarter phase relation, andfin `order to obtain the best results one piston isso 'connected to the crank shaft as to have a 4smaller extent of travel than the other, this being most readily accomplished by having thil respective cranks of dili'erentlengths.

The invention will be most read-ily understood by a descriiition of its application tov a two cycle type of engine, and hence the invention will be described with reference to the two cycle type of engine without, how ever. limiting the invention to such type. for the invention may be adapted to a four cycle ,type of engine by an appropriate change in the valve structure as is Well understood by those familiar with explosion engine practice.

While the description of the invention is based upon a showing of a practical form of explosion engine, it will be understood that the invention is by no means limited to the construction illustrated in the drawings, but such construction may be changed and modified so long as such changes and modifications mark no material departure from the salient features of the invention.

In the drawings Figure 1 is a section at right angles to the longitudinal axis of the crank shaft vof an engine embodying the present invention, the section being substantially diametric of the engine cylinder, some parts being shown in elevation. Fig. 2 is a section with some parts in elevation on a plane substantially at right angles to that of Fig. 1. Figs. 3, 4, 5 and 6 are elevations of the cylinder with parts broken away and in section showing different phases of operation of the piston.. Fig. 7 is a perspective view of the crank shaft.

lVhile doublev piston vexplosion engines wherein the pistons may reciprocate oppositely vwithin a single cylinder and both act upon a singlecrank shaft, have heretofore been proposed, such pistons have beenL so recate oppositcly in one hundred and eighty degreel relation one to the other, but in their relation'to the crank shaft such oppositely 'reciprocating pistons do not diHer from single reciprocating pistons and no provision is made for causing the explosive impulse to exert its greatest force when the crank shaft is in the most advantageous relation to the piston.

ln man v respects an engine embodying the present invention may be built in accordance with the customaryexplosion engine' practice, and in the drawings there is shown a cylinder 1 and a crank shaft 2, which latter, however, differs from the coinmon practice in having a crank 3 and other cranks l displaced circumferentially by i the cranks l are shorter than the crank 3,

that is, they are of less radial extent from connected up Hto the crank shaft as to recipin the upright or marinetype of engine may be utilized as a' support for the entire engine. The body member 6 may follow the usual engine practice whether the engine 1s to operate on the two cycle or four cycle principle, and although the engine illustrated in the drawings operates on the two cycle principle the body member is not utilized as a receiving and compressing chamber for either air or the explosive mixture, but these features are not material to the present invention and hence may be varied in accordance. with the wishes of the builder. The crank shaft 2 carries fly wheels 7, usually two in number, although this feature is not material to the present invention.

The cylinder 1 is shown as provided with a water jacket 8 as is customary, and also with a fuel inlet duct 9 and an exhaust duct 10 located approximately opposite each other at a point nearly midway of thelength of the cylinder, although the exact location of these parts depends upon the proportions of the crank shaft and other factors. Within the cylinder there are two pistons 11, 12, respectively, which may be of the same length, although this in itselfis not material, and each piston has the end or head facing the other piston hollowed out, as indicated at 13, 1 4, respectively, so that the facing heads of the two pistons may be brought into close relation with the hollowed out portions 13 and 14 together defining a chamber which, as will hereinafter appear, constitutes an explosion chamber, The piston 11 carries adeiector 15 between one edge of the piston and the center of the chamber 13, this deiiectorbeing of a length to enter the chamber 14 for the greater portion of the depth thereof when the pistons 11 and 12 are at their closest approach.` The piston 11 is provided with a piston rod 16 extending through a packing gland 17 in the head 18 of the cylinder 1 remote from the base 6, and this piston rod outside the cylinder is fast. to a cross head 19 moving in guides 20 mounted on the head 18, the 4cross head being of greater length than'the outside diameter of the cylinder 1 including the water jacket 8. The other piston 12 is connected by a pitman 21 with the crank 3, while the cranks 4 are each connected by a pitman 22 to a ,corresponding end of the cross head 19.

-The inlet duct or pipe 9 is connected' toa carbureter 23 or other suitable means for the supply of fuel and this carbureter is conlpiston rod l16 by a spark plug 26 having terminals 27 nected by a pipe 21 to the interior 'of the cylinder 1 between the piston 11 and the head 18 and furthermore' the pipe 24 is provided with an air inlet valve 25.

In the particular construction shown the is traversed longitudinally within the hollowed out portion13 of the piston 11 and contacts 28, 29, one carried by the cross head 19 and the other by one of the guides 20 serve as means for including' the spark plug in a suitable circuit for the production of a spark at the terminals 27 at the proper time for the ignition of a compressed 4explosive charge within the cylinder. While the spark plug is shown in the' drawings as carried by the piston rod 16, it will be understood'that it may be otherwise located and the energization of the spark plug otherwise controlled, so as to cause the ignition ofthe charge at the proper time.

The particular construction or disposition of the spark plug does not form any part of this invention, and hence it is deemedun necessaryI to describe the various ways in which the spark plug may be arranged,'the one shown being suflicient for an 'understanding of the operation of the invention.

If it be assumed that the parts are in the position shown in Figs. 1 and 2 with a compressed charge as of explosive mixture within the chamber delined'by the hollowed out portions 13 and 14, and that just before reaching this position the charge `has been fired by the passing of a vspark across the terminals 27, then by the time the parts have assumed the position shown in Fig. 1 the charge has become fully ignited and the' full force of the impulse is directed against both the pistons 11 and 12, but the piston 12 has its crank 3 on dead center. The piston 11, however, has its cranks '4 at the ninety degree position, so that the f ull force of the explosion acts on the cranks 4 at the most advantageous position, or the position of greatest leverage, and the effect of the explosion is transmitted to the crank shaft with an energy far in excess of that which occurs from an explosion of like degree or power taking place in an ordinary Asingle niston explosion engine where the piston is fully retracted and the full force of the explosion occurs, while the crank shaft is on dead center. The power stroke of the engine of the present invention is that caused by` the movement of the piston 11- toward the head 18, thus turning the crank shaft 2 counter-clockwise as viewed in Fig. 1. The rotative movement of the crank shaft is, of course, imparted to the crank 3 and by way of the piston rod 21 to the piston 12, and this piston travels in a direction away from the head 18 and also away from the piston 11, the explosion acting on the piston 12 in much the lsame manner as it does in the messie ordinary explosion engine., so that the irnpnlse acting on the crank shaft is similar to that of' the ordinary explosion engine with the added impulse due to the full force of thc explosion acting on the piston 11, and while the force of the explosion acts through the piston 1'1 with decreasing leverage as the cranks l approach the upper dead center, the action of the piston l2 is witn increasing leverage upon the crank' shaft 2, and? moreover, the piston 19 moves with greater speed than the piston l1 because of the greater length of the crank is the piston il moves toward the head i8 the air within the chamber between the 'piston ll and head is compressed and forced throiigh the pipe 2i and through the carburetor 23 and as soon as the duct 9 is uncovered by the movement of the piston ll toward the head lSthe compressed air with the fuel taken up in the carburetor 23 is injected with force into the now enlarged chamber formed hy the cavities i3 and 14 and the space between the corresponding heads of the pistonsj the relative positions of the parts at the completion of the power stroke of the piston l1 being indicated in Fig 3i Vll'hile the inlet port at the inner end of the duct 9 was being uncovered by the'movement of the piston ll on its-power stroke the outlet port at the inner end oi" the duct l0 has also been uncovered. 'lhe deiector l5, however, tends to direct the incoming stream of fuel under pressure away from the exhaust pipe or duct 10 and toward the retreating piston l2, thus in the manner common in two cycle engines scavenging the hurried gases from the interior of the cylinder and ont through the exhaust duct l0; l/Vhen the piston l1 has reached the. toll limit of the power stroke, thus uncovering` the inlet and exhaust ports,z the piston l@ has onlY moved a little more than haii its iull stroke or until the crank 3 has reached the ninety degree position from the upper dead; center, all as shown in Fig 3. On a further rotative movement of the crank shaft Jfrom the position shown in Fig. 3 to the position shown in Fig. 4., the piston 12 reaches its limitof movement awa7 from the head i8 and the piston 11 hasyalso traveled awa;7 from the head 18 for a little more than halie its stroke, or with the cranks 4- at the ninety degree position trom upper or lower dead center. The movement fot the piston li away from the head 18 tends to create a vacuum within the space between the pisA` ton li and head lll and atmospheric air is drawnin through the valve Now on the next quarter revolution'of the shaft 2 to the position shown in Fig. 5 the movement of the ypiston llhas continued until the cranks t are at lower dead centen thus marking the limit of movement of the piston llaway from the head i8. ln the meantime, the piston l2 has moved toward the head 18 and also toward the piston ll, thusl partially compressing the charge confined between the two pistons., Now, on a further-rotative movement of the crank shaft the piston l2.

continues its movement toward the head 18 and the piston ll begins its nioif'ement toward the head lo, The piston l27 however.Il moves with greater rapiditythan the piston 1l because of the greater length ot7 the crank 2l and hence the piston l2 approaches the piston ll and this approaching continues until the cranks have moved throngh an arc of about sixty-seven and onehaltz degreesZ after which the piston ll gradually draws away from the piston 1Q, until the crank 3 is on upper dead center. rl`he position of greatest approach ot the two pistons (see liig'. (l) is at a point within about twenty-two and one-halt" degrees et the position shown in Fig. l and at this position of greatest approach which is also the position oit greatest compression oi the charge theparts may he so timed that contact is made the contacts 28 and ilvin a manner to canse the passage oiga spark between the terminals 2?., wherefore the charge is ignited at the point of' greatest compression and is thoroughly inflamed throughout, and hence imparts its impulse at the time the crank 3 has reached upper dead center, such position of the parts .being shown in Fig. l5 and hence the full power stroke ot the piston ll begins under the most favorfv able conditions ot leverage of the crank shaft 2. of 'the compression after the passing of the spark and before the complete ignition ot' the charge, the loss thus caused is het a small fraction of the loss caused by the tiring ofthe explosive mixture in a single piston engine or in ay doiihle piston engine where the crank must pass the vdead center before the force of the explosion is at all active and must complete about one-half the power stroke before the crank is in the most effective positions, hut at which time the torce of the explosion has'been spent to a mate-rial extent without commensurate effect upon the crank shaft. The discharge of the hurned or spent gases takes hut onequarter ot a revolution of the crank shaft.a thas reserving three-fourths ota the revolution for the intake and assimilation oic the fuel mixtures This aids to a marked extent in the reduction of internal heat, wheres tore less cooling agent is required to keep the engine cool than would otherwise he the case and the cooling vproblem is .to a like extent simplifiedt Again9 during the intake oie fuel thepiston l@ is moving rapidilv awayT troni the intake and hence tends to create vacnnin conditions hy somewhat enlarging the area of the'chamher between the pistons and thus serves to retain all the fresh fuel li/Thile there is a slight reduction,

instead of more or less of it escaping through i readily understood by those familiar with l explosion engine practice, for the principles of the present invention are not confined to any single type of engine, but maybe used with either of the prevailing types. Nor is the engine limited to the use of a crank shaft for the same relation of movement ot' the pistons may be brought about with other forms of driving devices than crank shafts, it only being necessary that the pistons shall have movements related as described, that is, their movements shall be in quarter phase relation or such approach thereto as shall produce results such as are accomplished .by the quarter phase relation of 'movement herein set forth.

-While the engine has been shown in the drawings as an upright or marine type of engine, it will be understood that the same principles are applicable to a horizontal engine, or to a tandem engine of the explosion type, and hence the invention is not limited to any particular type of engine to the exclusion of all others.

Other structures such as eccentrics have been employed in place of cranks, and hence c a n eccentric shaft with the eccentrics suitably depliased may be employed in place of the crank shaft shown, but as such structures are well known expedients and considered as equivalents of crank shafts it is not deemed necessary to illustrate them, since the principles of theinvention are not dependent upon any specific mechanical structures.

What is claimed isil. In an explosion engine, a power cylinder provided with inlet and exhaust ports,

two coacting reciprocating pistons thereinl with one having a range of movement to cover and uncover the inlet yand exhaust ports, a driven member, and connections between the pistons and driven member constructed and related to cause the pistons to move in the same direction and in opposite directions during different phases of the operation of the engine.

Q. Atwo cycle explosion engine provided with a 'cylinder having inlet and outlet ports constituting the sole inlet 'and outlet ports of the explosion chamber of the engine, a power piston having a-range of movement to cover and uncover said ports, another inlet and outlet ports of the explosion chamber of the engine, a driven member, a piston mounted in the cylinder and connected to the driven member and having a range of movement to cover and uncover said inlet and outlet ports, said piston and cylinder being also constructed, to operate as a pump for compressing air for introduction into the cylinder on the explosion chamber side of the piston, and another piston mounted in the cylinder and connected to the driven member and related to the first-named piston to provide an explosion chamber between ythe two pistons, said last-named piston having its entire range of movement coniinedto a portion of the cylinder spaced from said ports.

4. An explosion engine of the two cycle type provided with a power cylinder having inlet and outlet ports constituting the sole inlet and outlet ports of the explosion cylinder of the engine, a driven member, a piston mounted in the cylinder and connected to the driven member and having a range of movement to cover and uncover said inlet and outlet ports, said piston and cylinder being also constructed to operate asa pump for compressing air for introduction into the cylinder on the explosion chamber side of the piston, and another piston mounted in and confined in its travel to a portion of' the cylinder spaced from said ports and con` nected to the driven member and related to the first-named piston to provide an explosion chamber between the two pistons, the irst-name'drpiston being provided with a deiector in position to direct fluid under pressure entering the cylinder through the inlet port toward the other piston.

5. An explosion engine of the two cycle typey comprising an axially elongated cylinder closed at one end and provided with inlet and exhaust ports adjacent to said closed end and also with an outlet communicating with thevinlet port of the cylinder, Isaid inlet and exhaust ports constituting the sole ports of the explosion chamber of the engine, a piston within the cylinder in position to move toward and from the closed end of the cylinder to form a pump and having a range of `movement to cover and uncover said inlet der having intermediate intake and exhaust ports, a pair of pistons within the cylinder,

' reciprocable on opposite sides of the ports and one piston having a range of movement to cover and uncover the ports,l and means for causing movements of the pistons in the same direction and in opposite directions during different periods of thecycle of operations, the cylinder and one of the pistons Vbeing related to cause a compression of the charge directed to the inlet port.

14. In an explosion engine, a power cylinder provided withinlet and exhaust ports intermediate thereof, a pair of pistons within the cylinder havingthe adjacent heads hollowed out to form part of an ex. chamber between the pistons, one

der provided with inlet and exhaust ports intermediate thereof, a pair, of pistons within the cylinder. having the adjacent plosion chamber between the pistons, one piston and one end of the cylinder being related to serve as a pumpvand said end of the Y'cylinder being connected to the inlet port of the cylinder, a crank shaft having cranks relatively displacedv approxi# mately ninety degrees, and connections between the cranks and respective pistons to cause movements of the pistons in accordance with the displacement of the cranks, the crank connected. to one piston being shorter than that connected to the other piston to cause a corresponding difference in travel of the pistons.

In testimony that I claim the foregoing as my own, I have hereto affixed my signature in the presence of two witnesses. HENRY -THOMAS CREW. Ilitnesses':

J. A. STYRoN, W. E. MAR'rlN.

`v heads hollowed out to form part of an ex- 

